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Nikonova E, DeCata J, Canela M, Barz C, Esser A, Bouterwek J, Roy A, Gensler H, Heß M, Straub T, Forne I, Spletter ML. Bruno 1/CELF regulates splicing and cytoskeleton dynamics to ensure correct sarcomere assembly in Drosophila flight muscles. PLoS Biol 2024; 22:e3002575. [PMID: 38683844 PMCID: PMC11081514 DOI: 10.1371/journal.pbio.3002575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Revised: 05/09/2024] [Accepted: 03/04/2024] [Indexed: 05/02/2024] Open
Abstract
Muscles undergo developmental transitions in gene expression and alternative splicing that are necessary to refine sarcomere structure and contractility. CUG-BP and ETR-3-like (CELF) family RNA-binding proteins are important regulators of RNA processing during myogenesis that are misregulated in diseases such as Myotonic Dystrophy Type I (DM1). Here, we report a conserved function for Bruno 1 (Bru1, Arrest), a CELF1/2 family homolog in Drosophila, during early muscle myogenesis. Loss of Bru1 in flight muscles results in disorganization of the actin cytoskeleton leading to aberrant myofiber compaction and defects in pre-myofibril formation. Temporally restricted rescue and RNAi knockdown demonstrate that early cytoskeletal defects interfere with subsequent steps in sarcomere growth and maturation. Early defects are distinct from a later requirement for bru1 to regulate sarcomere assembly dynamics during myofiber maturation. We identify an imbalance in growth in sarcomere length and width during later stages of development as the mechanism driving abnormal radial growth, myofibril fusion, and the formation of hollow myofibrils in bru1 mutant muscle. Molecularly, we characterize a genome-wide transition from immature to mature sarcomere gene isoform expression in flight muscle development that is blocked in bru1 mutants. We further demonstrate that temporally restricted Bru1 rescue can partially alleviate hypercontraction in late pupal and adult stages, but it cannot restore myofiber function or correct structural deficits. Our results reveal the conserved nature of CELF function in regulating cytoskeletal dynamics in muscle development and demonstrate that defective RNA processing due to misexpression of CELF proteins causes wide-reaching structural defects and progressive malfunction of affected muscles that cannot be rescued by late-stage gene replacement.
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Affiliation(s)
- Elena Nikonova
- Biomedical Center, Department of Physiological Chemistry, Ludwig-Maximilians-Universität München, München, Germany
| | - Jenna DeCata
- School of Science and Engineering, Division of Biological and Biomedical Systems, Kansas City, Missouri, United States of America
| | - Marc Canela
- Faculty of Biology, Universitat de Barcelona, Barcelona, Spain
| | - Christiane Barz
- Muscle Dynamics Group, Max Planck Institute of Biochemistry, München, Germany
| | - Alexandra Esser
- Biomedical Center, Department of Physiological Chemistry, Ludwig-Maximilians-Universität München, München, Germany
| | - Jessica Bouterwek
- Biomedical Center, Department of Physiological Chemistry, Ludwig-Maximilians-Universität München, München, Germany
| | - Akanksha Roy
- Biomedical Center, Department of Physiological Chemistry, Ludwig-Maximilians-Universität München, München, Germany
| | - Heidemarie Gensler
- Department of Systematic Zoology, Biocenter, Faculty of Biology, Ludwig-Maximilians-Universität München, München, Germany
| | - Martin Heß
- Department of Systematic Zoology, Biocenter, Faculty of Biology, Ludwig-Maximilians-Universität München, München, Germany
| | - Tobias Straub
- Biomedical Center, Bioinformatics Core Unit, Ludwig-Maximilians-Universität München, München, Germany
| | - Ignasi Forne
- Biomedical Center, Protein Analysis Unit, Ludwig-Maximilians-Universität München, München, Germany
| | - Maria L. Spletter
- Biomedical Center, Department of Physiological Chemistry, Ludwig-Maximilians-Universität München, München, Germany
- School of Science and Engineering, Division of Biological and Biomedical Systems, Kansas City, Missouri, United States of America
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Harriot AD, Altair Morris T, Vanegas C, Kallenbach J, Pinto K, Joca HC, Moutin MJ, Shi G, Ursitti JA, Grosberg A, Ward CW. Detyrosinated microtubule arrays drive myofibrillar malformations in mdx muscle fibers. Front Cell Dev Biol 2023; 11:1209542. [PMID: 37691825 PMCID: PMC10485621 DOI: 10.3389/fcell.2023.1209542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 08/09/2023] [Indexed: 09/12/2023] Open
Abstract
Altered myofibrillar structure is a consequence of dystrophic pathology that impairs skeletal muscle contractile function and increases susceptibility to contraction injury. In murine Duchenne muscular dystrophy (mdx), myofibrillar alterations are abundant in advanced pathology (>4 months), an age where we formerly established densified microtubule (MT) arrays enriched in detyrosinated (deTyr) tubulin as negative disease modifiers impacting cell mechanics and mechanotransduction. Given the essential role of deTyr-enriched MT arrays in myofibrillar growth, maintenance, and repair, we examined the increased abundance of these arrays as a potential mechanism for these myofibrillar alterations. Here we find an increase in deTyr-tubulin as an early event in dystrophic pathology (4 weeks) with no evidence myofibrillar alterations. At 16 weeks, we show deTyr-enriched MT arrays significantly densified and co-localized to areas of myofibrillar malformation. Profiling the enzyme complexes responsible for deTyr-tubulin, we identify vasohibin 2 (VASH2) and small vasohibin binding protein (SVBP) significantly elevated in the mdx muscle at 4 weeks. Using the genetic increase in VASH2/SVBP expression in 4 weeks wild-type mice we find densified deTyr-enriched MT arrays that co-segregate with myofibrillar malformations similar to those in the 16 weeks mdx. Given that no changes in sarcomere organization were identified in fibers expressing sfGFP as a control, we conclude that disease-dependent densification of deTyr-enriched MT arrays underscores the altered myofibrillar structure in dystrophic skeletal muscle fibers.
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Affiliation(s)
- Anicca D. Harriot
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Tessa Altair Morris
- Center for Complex Biological Systems, Edwards Lifesciences Foundation Cardiovascular Innovation and Research Center, and the NSF-Simons Center for Multiscale Cell Fate Research, University of California, Irvine, Irvine, CA, United States
| | - Camilo Vanegas
- Department of Orthopedics, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Jacob Kallenbach
- Department of Orthopedics, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Kaylie Pinto
- Department of Molecular Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Humberto C. Joca
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Marie-Jo Moutin
- INSERM U1216 Centre National de la Recherche Scientifique, Grenoble Institut Neurosciences, University Grenoble Alpes, Grenoble, France
| | - Guoli Shi
- Department of Orthopedics, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Jeanine A. Ursitti
- Department of Orthopedics, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Anna Grosberg
- Center for Complex Biological Systems, Edwards Lifesciences Foundation Cardiovascular Innovation and Research Center, and the NSF-Simons Center for Multiscale Cell Fate Research, University of California, Irvine, Irvine, CA, United States
- Department of Biomedical Engineering, Sue and Bill Gross Stem Cell Research, University of California, Irvine, Irvine, CA, United States
- Department of Chemical and Biomolecular Engineering, Sue and Bill Gross Stem Cell Research, University of California, Irvine, Irvine, CA, United States
| | - Christopher W. Ward
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, United States
- Department of Orthopedics, University of Maryland School of Medicine, Baltimore, MD, United States
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Grande V, Schuld J, van der Ven PFM, Gruss OJ, Fürst DO. Filamin-A-interacting protein 1 (FILIP1) is a dual compartment protein linking myofibrils and microtubules during myogenic differentiation and upon mechanical stress. Cell Tissue Res 2023:10.1007/s00441-023-03776-4. [PMID: 37178194 DOI: 10.1007/s00441-023-03776-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 04/19/2023] [Indexed: 05/15/2023]
Abstract
Variations in the gene encoding filamin-A-interacting protein 1 (FILIP1) were identified to be associated with a combination of neurological and muscular symptoms. While FILIP1 was shown to regulate motility of brain ventricular zone cells, a process important for corticogenesis, the function of the protein in muscle cells has been less well characterized. The expression of FILIP1 in regenerating muscle fibres predicted a role in early muscle differentiation. Here we analysed expression and localization of FILIP1 and its binding partners filamin-C (FLNc) and microtubule plus-end-binding protein EB3 in differentiating cultured myotubes and adult skeletal muscle. Prior to the development of cross-striated myofibrils, FILIP1 is associated with microtubules and colocalizes with EB3. During further myofibril maturation its localization changes, and FILIP1 localizes to myofibrillar Z-discs together with the actin-binding protein FLNc. Forced contractions of myotubes by electrical pulse stimulation (EPS) induce focal disruptions in myofibrils and translocation of both proteins from Z-discs to these lesions, suggesting a role in induction and/or repair of these structures. The immediate proximity of tyrosylated, dynamic microtubules and EB3 to lesions implies that also these play a role in these processes. This implication is supported by the fact that in nocodazole-treated myotubes that lack functional microtubules, the number of lesions induced by EPS is significantly reduced. In summary, we here show that FILIP1 is a cytolinker protein that is associated with both microtubules and actin filaments, and might play a role in the assembly of myofibrils and their stabilization upon mechanical stress to protect them from damage.
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Affiliation(s)
- Valentina Grande
- Institute for Cell Biology, University of Bonn, Ulrich-Haberland-Str. 61a, 53121, Bonn, Germany
| | - Julia Schuld
- Institute for Cell Biology, University of Bonn, Ulrich-Haberland-Str. 61a, 53121, Bonn, Germany
| | - Peter F M van der Ven
- Institute for Cell Biology, University of Bonn, Ulrich-Haberland-Str. 61a, 53121, Bonn, Germany
| | - Oliver J Gruss
- Institute of Genetics, University of Bonn, Karlrobert-Kreiten-Str. 13, 53115, Bonn, Germany
| | - Dieter O Fürst
- Institute for Cell Biology, University of Bonn, Ulrich-Haberland-Str. 61a, 53121, Bonn, Germany.
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Zapater I Morales C, Carman PJ, Soffar DB, Windner SE, Dominguez R, Baylies MK. Drosophila Tropomodulin is required for multiple actin-dependent processes within developing myofibers. Development 2023; 150:dev201194. [PMID: 36806912 PMCID: PMC10112908 DOI: 10.1242/dev.201194] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 02/09/2023] [Indexed: 02/22/2023]
Abstract
Proper muscle contraction requires the assembly and maintenance of sarcomeres and myofibrils. Although the protein components of myofibrils are generally known, less is known about the mechanisms by which they individually function and together synergize for myofibril assembly and maintenance. For example, it is unclear how the disruption of actin filament (F-actin) regulatory proteins leads to the muscle weakness observed in myopathies. Here, we show that knockdown of Drosophila Tropomodulin (Tmod), results in several myopathy-related phenotypes, including reduction of muscle cell (myofiber) size, increased sarcomere length, disorganization and misorientation of myofibrils, ectopic F-actin accumulation, loss of tension-mediating proteins at the myotendinous junction, and misshaped and internalized nuclei. Our findings support and extend the tension-driven self-organizing myofibrillogenesis model. We show that, like its mammalian counterpart, Drosophila Tmod caps F-actin pointed-ends, and we propose that this activity is crucial for cellular processes in different locations within the myofiber that directly and indirectly contribute to the maintenance of muscle function. Our findings provide significant insights to the role of Tmod in muscle development, maintenance and disease.
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Affiliation(s)
- Carolina Zapater I Morales
- Biochemistry, Cell & Developmental Biology, and Molecular Biology (BCMB) program, Weill Cornell Graduate School of Medical Sciences, New York, NY 10065, USA
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering, Cancer Center, New York, NY 10065, USA
| | - Peter J Carman
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - David B Soffar
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering, Cancer Center, New York, NY 10065, USA
| | - Stefanie E Windner
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering, Cancer Center, New York, NY 10065, USA
| | - Roberto Dominguez
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Mary K Baylies
- Biochemistry, Cell & Developmental Biology, and Molecular Biology (BCMB) program, Weill Cornell Graduate School of Medical Sciences, New York, NY 10065, USA
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering, Cancer Center, New York, NY 10065, USA
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5
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Lucas L, Cooper TA. Insights into Cell-Specific Functions of Microtubules in Skeletal Muscle Development and Homeostasis. Int J Mol Sci 2023; 24:ijms24032903. [PMID: 36769228 PMCID: PMC9917663 DOI: 10.3390/ijms24032903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 01/17/2023] [Accepted: 01/31/2023] [Indexed: 02/05/2023] Open
Abstract
The contractile cells of skeletal muscles, called myofibers, are elongated multinucleated syncytia formed and maintained by the fusion of proliferative myoblasts. Human myofibers can be hundreds of microns in diameter and millimeters in length. Myofibers are non-mitotic, obviating the need for microtubules in cell division. However, microtubules have been adapted to the unique needs of these cells and are critical for myofiber development and function. Microtubules in mature myofibers are highly dynamic, and studies in several experimental systems have demonstrated the requirements for microtubules in the unique features of muscle biology including myoblast fusion, peripheral localization of nuclei, assembly of the sarcomere, transport and signaling. Microtubule-binding proteins have also been adapted to the needs of the skeletal muscle including the expression of skeletal muscle-specific protein isoforms generated by alternative splicing. Here, we will outline the different roles microtubules play in skeletal muscle cells, describe how microtubule abnormalities can lead to muscle disease and discuss the broader implications for microtubule function.
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Affiliation(s)
- Lathan Lucas
- Chemical, Physical, Structural Biology Graduate Program, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Thomas A. Cooper
- Chemical, Physical, Structural Biology Graduate Program, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular & Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
- Correspondence:
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The actin polymerization factor Diaphanous and the actin severing protein Flightless I collaborate to regulate sarcomere size. Dev Biol 2021; 469:12-25. [PMID: 32980309 DOI: 10.1016/j.ydbio.2020.09.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 09/15/2020] [Accepted: 09/19/2020] [Indexed: 12/22/2022]
Abstract
The sarcomere is the basic contractile unit of muscle, composed of repeated sets of actin thin filaments and myosin thick filaments. During muscle development, sarcomeres grow in size to accommodate the growth and function of muscle fibers. Failure in regulating sarcomere size results in muscle dysfunction; yet, it is unclear how the size and uniformity of sarcomeres are controlled. Here we show that the formin Diaphanous is critical for the growth and maintenance of sarcomere size: Dia sets sarcomere length and width through regulation of the number and length of the actin thin filaments in the Drosophila flight muscle. To regulate thin filament length and sarcomere size, Dia interacts with the Gelsolin superfamily member Flightless I (FliI). We suggest that these actin regulators, by controlling actin dynamics and turnover, generate uniformly sized sarcomeres tuned for the muscle contractions required for flight.
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Bandyopadhyay A, Francis-West P, Katti D, Roselló-Díez A. Musculoskeletal Development, Maintenance and Regeneration: Part One. Dev Dyn 2020; 250:6-7. [PMID: 33295101 DOI: 10.1002/dvdy.277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Amitabha Bandyopadhyay
- Department of Biological Sciences and Bioengineering and The Mehta Family Centre for Engineering in Medicine, Indian Institute of Technology Kanpur, Kanpur, India
| | - Philippa Francis-West
- Centre for Craniofacial and Regenerative Biology, Faculty of Dentistry, Oral and Craniofacial Sciences, Kings College London, London, UK
| | - Dhirendra Katti
- Department of Biological Sciences and Bioengineering and The Mehta Family Centre for Engineering in Medicine, Indian Institute of Technology Kanpur, Kanpur, India
| | - Alberto Roselló-Díez
- Australian Regenerative Medicine Institute, Monash University, Clayton, Victoria, Australia
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